Substance Over Form: How The Delhi And Madras High Courts Are Rewriting The Rules For Global Patent Applicants In India

This appellate scrutiny is increasingly important for global applicants. Many companies first file patent applications abroad and later seek protection in India. They may assume that success in other jurisdictions will carry weight here. Recent Indian case law shows otherwise. The courts are insisting on better reasoning from the Patent Office, but they are also reminding applicants that Indian statutory exclusions remain strict.

Inventive step requires reasons, not conclusions

Inventive step means more than novelty. An invention may be new and still fail if it would have been obvious to a skilled person. In Microsoft Technology Licensing LLC v Assistant Controller of Patents and Designs, 2024 SCC OnLine Mad 285, the Madras High Court set aside a refusal concerning efficient communication of sensor data to subscribing applications. The Court found that the Controller had not properly examined whether the prior art taught or suggested the claimed solution.

The same concern appears in Tapas Chatterjee v Controller, Patents and Designs. The Delhi High Court criticised a mechanical approach to inventive step and reiterated that the Patent Office must identify the prior art, compare it with the claimed invention and explain why the skilled person would arrive at the invention without inventive ingenuity. For applicants, a response to an examination report must therefore explain the technical advance and the gap in the prior art.

Healthcare inventions and Section 3(i)

Section 3(i) excludes methods of treatment of human beings or animals. The difficulty arises in medical technology and diagnostic inventions, where an invention may assist doctors but may not itself be a method of treatment. In EMD Millipore Corporation v Assistant Controller of Patents and Designs, Neutral Citation 2025:DHC:8928, the Delhi High Court treated Section 3(i) as a targeted exclusion, not a broad bar against every invention connected with healthcare.

The distinction is practical. If the claim is drafted as a step performed by a clinician on a patient, Section 3(i) risk increases. If the claim is directed to a machine, reagent, assay or data generating process, the analysis may be different. The lesson is not that all diagnostic inventions are patentable. The lesson is that the legal character of the claim matters.

Software, artificial intelligence and Section 3(k)

Guidelines for Examination of Computer Related Inventions, 2025, Office of the Controller General of Patents, Designs and Trade Marks, available at IP India CRI Guidelines 2025.

Caleb Suresh Motupalli v Controller of Patents, 2025:MHC:293, is a useful caution. The Madras High Court declined to interfere with refusal of an application that claimed integration of human and artificial intelligence capabilities. The claims were found vague and metaphorical, and the specification did not properly explain how the promised result would be achieved. A claim cannot merely invoke artificial intelligence as a label. It must disclose a workable method, the technical problem and the technical effect.

Pharmaceutical patents and divisional applications

Pharmaceutical patents continue to face a strict standard. Section 3(d) prevents patents for new forms of known substances unless enhanced therapeutic efficacy is shown. In Zeria Pharmaceutical Co Ltd v Assistant Controller of Patents and Designs, 2025 SCC OnLine Del 4015, the Delhi High Court upheld refusal of a divisional application for an intermediate compound where the claim could not cross the statutory and inventive step thresholds. Incremental pharmaceutical inventions require evidence and careful claim drafting, not merely structural variation.

Divisional applications are also important. A divisional application is filed when one patent application contains more than one invention and the applicant separates one invention into a further application. In Syngenta Ltd v Controller of Patents and Designs, 2023:DHC:7473 DB, the Delhi High Court Division Bench held that plurality of inventions may be gathered from the provisional or complete specification, not only from the claims of the parent application. This helps applicants, but only where the original specification clearly discloses the separate invention.

The broader message for Indian patent practice

Taken together, these decisions show a balanced judicial trend. The High Courts are not permitting the Patent Office to refuse applications through sparse or formulaic reasoning. At the same time, they are not diluting India's exclusions on software, medical treatment, evergreening or insufficient disclosure. The result is a more disciplined patent system.

For inventors, start ups, research institutions and global companies, the practical lesson is simple. India cannot be treated as a routine filing destination. The application must explain the invention in clear technical terms. The claims must match the disclosure. The response to objections must answer the law and the science. If the matter reaches the High Court, the record built before the Patent Office may decide the case.

Recent patent case law is therefore not just a specialist debate. It affects innovation policy, access to technology, healthcare inventions, software development and foreign investment in India. The courts are asking both sides of the patent system to do better. Controllers must give reasoned decisions. Applicants must present real inventions with real disclosure. That is a welcome development for Indian patent law.

References

Microsoft Technology Licensing LLC v Assistant Controller of Patents and Designs, 2024 SCC OnLine Mad 285.

Tapas Chatterjee v Controller, Patents and Designs, 2025 LiveLaw (Del) 1259.

EMD Millipore Corporation v Assistant Controller of Patents and Designs, Neutral Citation 2025:DHC:8928.

Guidelines for Examination of Computer Related Inventions, 2025, Office of the Controller General of Patents, Designs and Trade Marks, available at IP India CRI Guidelines 2025.

Caleb Suresh Motupalli v Controller of Patents, 2025:MHC:293.

Zeria Pharmaceutical Co Ltd v Assistant Controller of Patents and Designs, 2025 SCC OnLine Del 4015.

Syngenta Ltd v Controller of Patents and Designs, 2023:DHC:7473 DB.